Concrete arch construction.



No. 799,794. Patented snpt 23, |902.

w. c. PARMLEY.

CONCRETE ARCH CONSTRUCTION.

(Application flled Feb. 25, 1902.)

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4 Sheets-Shaet l.

`A TTORNEK No. 709,794. Patented Sept. 23, |992. W. C. PARMLEY. CONCRETEARCH CONSTRUCTION.

(Application med Feb. 25, 1902.)

4 Sheath-Sheet 2.

(No Model.)

WITNESSES; C2. INVENTOR. p75 BY ;N

1;1: Ncnms PETERS co, PHoroLn'no., wAsHmcmN. DA c.

Patented Sept. 23, |902.

w. c. -PARMLEY. CCNCRETE ARCH CONSTRUCTION.

(Application led Feb.` 25, 1902.)

4 Sheeis-Sheet 3.`

(No Model.)

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50M I /NVETOR A TTORNE Y.

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No. 709,794. Patented Sept. 23,. |902.

' W. C. PARMLEY.

CONCRETE ARCH CONSTRUCTION.

(Application led Feb. 25, 1902.)

` 4 Sheets-Sheet 4.

(No Modem WIM/55555. l @afd-' C. MIME/WOR. `w BY 55M. W f3 ATTORNEX TH:Nbnms PzTens cu, worn-umn., wAsulNuT-DN, n. c.

` Marten @tratas -araat Ormea VAI/lER C. IARMLEY, OF CLEVELAND, OHIO.

CONCRETE ARCH CONSTRUCTION.

SPECIFICATION forming part of Letters Patent No. 709,794, datedSeptember 23, 1:902.

Application tiled February 25,19-(22y Serial No. 95,603. (No model.)

To all whom it mag/concerne Beit known that I, lVALTER C. PARMLEY, acitizen of the United States, residing at Cleveland, in the county ofCuyahoga and State of Ohio, have invented a new and useful Improvementin Concrete Arch Constructions, of which the followingr is aspeciiication.

This invention relates in general to concrete arch construction, and hasparticular reference to certain new and useful combinations of metalbars, rods, shapes, the., with the masonry or cement of the arch. It hasbeen customary to insert in an arch bars, tbc., which are so embeddedtherein as to resist more or less perfectly the bending moments producedlaterally or in a plane transversely to the axis of the arch, suchastructure being shown and described in my pending application, tiledJune 4, 1901, Serial No. (55,000.

This structure while it maybe made to meet all the requirements foruniform loading and also in cases where the various strains can beexactly calculated is not perfectly suited toarcheswhen the loads areVariable, and this is the condition almost uniformly met with inpractice. In nearly all cases the loads are more or less irregularlyapplied to the arch structure, and hence they produce an irregularity inthe positions and directions of the various thrusts and bending moments.Furthermore, it is practically impossible to build a concrete or masonrystructure that is homogeneous throughout, there being planes and linesol weakness due to irregularities in the quality of the material or inthe workmanship. In {.ilacing metal bars, tbc., in a structure of this`character it becomes important, therefore, to give duc consideration toall these irregularities iu the strains and in the materials and to soplace` the bars as to make'tlie arch capable of withstanding all thestrains to which it may be subjected.

In the acct'unpanyingd rawings, which illustrate my preferred lforms ot'arrangement of the bars, tbc., Figure l represents in sectionalelevation, and Fig. 2 in plan, an arch in which transverse bars arepassed through all the regions ol tension in both the intl-ados andextrados and are combined with longitudinal bars extending parallel withthe axis of the arch, some of said bars being placed at pointsintermediate the tensional regions and the others at different points.Fig. 3 shows in sectional elevation a segmental arch of less than asemicircle, the arrangement of the various bars being substantially thesame as in the upper part of the arch shown in Figs. l and 2. Fig. 4t isa sectional elevation of an arch `that has a continuous transverse barpassing along the intrados andi shorter bars each passing through butone region ot' tension in the extrados, said bars being combined withother bars extending substantially parallel with the axis of the arch.Fig. 5 is a sectional elevation of an arch similar to that shown in Fig.4, but having a somewhat-dit`ferent arrangement of the longitudinalbars. Fig. (5 shows an arch similar to that illustrated in Figs. t and5. Fig. 7 is a sectional elevation of a form of arch that has continuous bars passing through the intrados and other bars connectedtherewith at suitable poiuts and passing through the arch to theextrados, all of said bars extending into the abutments and beingcombined with longitudinal bars. Fig. S shows a 'form of arch that hascontinuous bars passing around in both the intrados and extradossaidbars being connected through the arch bya web system and being combinedwith longitudinal bars. Fig. 9 is a sectional elevation of an arch having bars that pass continuously through all the regions of tension inboth intradosand extrados and other transverse bars that pass throughthe tensional regions near the base ol' the ext/ratlos and then throughthe tensional region in the intl-ados at the crown, said bars being incombination with .the longitudinal bars.Y Fig. l0 illustrates an archthat has continuous bars passing through all the regions ot' tension inthe intrados and extrados an d other transverse bars reinforcing thecontinuous bars at the crown and also at the abutments, said bars beingin combination with the longitudinal bars. Fig. l1 shows a form ot archhaving bars passing continuously through the intrados and other barspassing continuously from the entrados at the abutments through the archand through the region ot tension in the intrados at the crown, saidbars, as before, being combined with ICO those extending parallel withthe axis of the arch. Fig. 12 is a sectional view of an arch similar tothat shown in Fig. 9 except that the bar, which in that figure extendedinto the eXtrados at or near the abutments, is carried continuouslythrough the intrados. Fig. 13 shows a transverse and Fig. 14 alongitudinal section through a form of tubular arch in which acontinuous transverse bar is placed spirally about the tube within theconcrete substantially midway between the intrados and eXtrados. Withthis bar are combined a plurality of longitudinal bars, as shown. Fig.v15 is a transverse, Fig. 16 a longitudinal, section of a form of arch.similar to that shown in Figs. 14 and 15, but having two continuous barspassing spirally about within the concrete, one of the spirals beingarranged within the other and both being combined withlongitudinalbars.Preferablyonebaris wound into a right-hand and the other into bedesirable in the particular case.

a left-hand spiral, as shown. Fig. 17 is a perspective view of the forniof arch shown in Fig. l, illustrating the connections between thetransverse and longitudinal bars. Fig. 18 is a similar viewof theformshown in Figs. 4, 5, &c. Fig. 19 is a longitudinal section throughthe arch, showing the transverse and longitudinal bars connected atpoints intermediate the tensional regions; and Fig. 20 is a transversesection of the same.

. Similar reference charactersdesignate corresponding parts throughoutthe several views of the drawings.

As stated, the conditions met with in actual practice render itimpossible to calculate to a certainty the thrusts and stresses to whichan arch structu re will be subjected. This is due to a number of facts,such as moving loads, irregularities in material and workmanship,differences in the character of the abutmenls,an l unequalsettlingot'theground about the arch. It thus becomes necessary to t'ormthe arch structurein such away that it will withstand all the stressesto'which it may be subjected at any point. In general I accomplish thisresult by inserting longitudinal bars, rods, or shapes transversely tothe main tension rods, bars, or shapes or in the direction of the axisof the arch and by securing the two systems of bars together at. theirpoints of intersection or not, as may In an arch not reinforced by asystem of longitudinal bars the structure immediately underneath aconcentrated or excessive load will be subjected to greater strains thanthe remaining portions of the arch, and undue deltlection,crackin t,r,or, in extreme cases, failure may result. When the longitudinal bars areinserted, however, they distribute the excessive strains over a greaterportion of the arch and to a greater number ot' Imain supportingbars,thereby greatly increasing the strength of the arch. It will beunderstood that the number of both transverse and longitudinal bars andalso the disposition of the same must vary with the particularconditions that are present, and that in a long arch, as a sewer, whenthe loads and the embedding earth vary in character, the bars will beadded and disposed so as to withstand the strains at all points, beingmost numerous at the points of possible emergency.

In Figs. 1 and 2, A A represent the main transverse bars,which passcontinuously from the intrados near the abutments through the neutralregions to the eXtrados and again through the arch to the intrados atthe crown. These bars thus pass through all the regions of tension inboth intrados and extrados. Combined with these bars are longitudinalbars B B, which are embedded in the arch between these regions oftension, bars C C,which are placed opposite the points of tension in theextrados, and bars D D, which occupy positions on each side of the archnear the crown and preferably in the region of tension in the intrados.The bars B B are or are not connected with the transverse bars A, as maybe preferred. 'Ihis form of arch is very economical owing to the smallamount of metal present, and is a very good form to employ where thevload is applied at the crown. Fig. 3 shows a segmental arch having thesame arrangement of bars as is shown in the upper part of Fig. 1 andbeing useful under the same or similar conditions. In this figure but apart of the transverse bars A appear, and these are designated E.

At this point it may be stated that inasmuch as the longitudinal barsrun parallel with the axis and with one another it is not deemednecessary to multiply the drawings by showing plan views ot' each form,as such views would differfroni Fig. 3 only in the location of thelongitudinal bars, and the locations ot' these parts are shown in thesectional views. The rst form thus described would be poorly adapted tosustain a concentrated load applied at points midway between the crownand the abutments or opposite the bars C owing to the fact that therewouldv be no transverse bar in the region of greatesttension, said barbeing at that point in the extrados and in the region of compression.When such loads are or may be applied or when it is impossible toforesee and calculate the strains in the arch, it is preferable to adoptthe form shown in Fig. S, in which continuous bars F and G pass throughthe intrados and extra- (los, respectively, or the forms shown in Figs.It, 5, and o, which may be regarded as modiiications ot' the form shownin said Fig. 8, requiring less material, and hence preferable undercertain conditions. In each of these forms the bars F pass continuouslythrough the intl-ados, as in Fig. 8; but instead ot' having continuousbars in the extrados, as in that figure, I use short bars H, each ofwhich pass through a region ot' tension and tar enough beyond the saineto secure firm anchorage.

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Fig. 5 shows a somewhat-different location for the bars H from thatshown in Figs. 4 and 6, as the bars are placed in the regions of tensionthe locations of which vary with the loads. It will be understood thatinstead of having the continuous bars in the intrados and the shorterbars in the eXtrados, as shown, the positions of these bars may bereversed, thus placing the continuous bars in the eXtrados.

Combined with the transverse bars F and H, as shown in Figs. 4 and 5,are the longitudinal bars D D, which, as in the forms heretoforedescribed, are embedded in the intrados on opposite sides near thecrown, the bars C C, which are placed opposite the regions of tension inthe eXtrados, and the bars B, which are located intermediate the regionsof tension. In the forni shown in Fig. 6 the bars D are omitted, and asingle bar D is employed at the crown in the intrados. In these formsthe bars B, C, and D may be secured to the bars F if desired, therebymaking a complete system of connected lateral and longitudinal bars. Thebars I-I, however, are not connected with the other bars, but areembedded in the concrete at the regions of tension in the eXtrados. Incertain cases of arch construction this would be the preferredarrangement.

In Fig. 7 the bars F extend continuously along the intrados, or if theeXtrados should be subjected to the greater number of tensional strainsthe bars G, as shown in Fig. 8, would be employed instead. Connected tothe bars F in a suitable manner at the points intermediate betweentensional regions, are bars J, which pass through the body of the l archand along the opposite side through the region subjected to tension.This is a valuable arrangement of transverse bars in cases of archeshaving insufiicient stability of abutment against the thrust of the archlaterally, for the strains in bars .I are opposed and neutralizedthrough their connection with bars F near the crown of the arch.Combined with these bars are the longitudinal bars D and C, which, as inthe forms heretofore described, lie in the intrados on opposite sides ofthe crown and opposite the regions of tension in the extrados,respectively. These bars may or may not be connected with the bars F. Inaddition to these bars are other longitudinal bars B, which are insertedto help distribute an unequal loading over a greater length of arch. Thebars B are located between the tensional regions in the intrados and arepreferably connected with the bars F.

Fig. 8 will serve to illustrate several difterent combinations oftransverse and longitudinal bars. In order to provide for all possibledistributions of loading, I may pass bars F and G continuously aroundthe intrados and extrados of the arch in the same vertical plane, andfor the purpose of further assisting the concrete in transferring thestrains from the crown to the abutinents I may, if found desirable,connect the bars by a web system, as shown at L. Combined with thesebars is a longitudinal bar D', as shown in Fig. G, the bars B Bintermediate points of tension, the bars IVI M in the extrados oppositethe bars B, and the bars N in both intrados and eXtrados at theabutments. The longitudinal bars may or may not be connected with thetransverse bars, as preferred. Bars F and G may also be alternated byplacing the bars G over the spaces between bars F. In this case the websystem L is omitted or is made by passing bars diagonally up ward anddownward from one set of bars to the other. By these combinations allpossible irregularities and changes in the loading are provided for anddistributed to the greatest possible length of arch for support.

In the forms of arches shown in both Figs. 9 and l0 the serpentine barsA(shown in Fig. l) are employed. In the first arch these bars arecombined with bars O, that pass from the estrados at the abutmentsupwardly and inwardly to the intrados at the crown, thus, extendingthrough but one region of tension in the intrados, while the bar A forthe same disposition of load will pass through all the regions oftension in both intrados and eX- trades. Bar A is normally in tensionfor uniform vertical loads when the abutments are rigid; but bar Oaffords a tensional support when there are unequal loads or where thereis not sul'iicient strength or rigidity laterally or vertically in theabutments. Combined with bars A and O are the longitudinal bars Bdescribed in connection with the arch shown inlFig. l andthe bars N usedin the extrados of the arch shown in Fig. 8. Bars C almost opposite theregion of tension in the entrados are also employed, said barscorresponding to bars C in Fig. l. The transverse and longitudinal barsmay be secured together at their points of intersection, it' preferred.This arch possesses a very great strength in proportion to the amount ofmetal employed. Bars A and C may alternate, or a greater number of onekind than the other may be used to meet the conditions for anyparticular case.

Fig. l0 shows a form that is similar to that just described and which isadapted to meet the same general requirements. Instead, however, ofhaving continuous bars O pass ing through a tensional region in theextrados and then through the arch into the intrados I employ aplurality of bars H, as shown in Figs. Li, 5, and 6, in the entradosnear the abutinents, said bars extending through thc tensional regionsthere and far enough beyond to secure anchorage. These bars assist insustaining the strains from unequal loading, from yielding abutments, orfrom insufficient lateral supports. While the bars A are intended tosustain the principal tensional loads, I reinforce them at the crown IOOIIO

by placing bars P in the intrados, said bars passing through the regionof tension and some distance beyond. Bars H and P may be placed inalternation with bars A or directly opposite the same, as desired, andthey may be inserted as frequently as is deemed necessary to support theload on the arch. This arrangement of bars is adapted for cases wherethe dead-load varies along dierent portions of the arch, for asufficient number of bars A may be inserted to provide for the normal orminimum strains and the arch strengthened where necessary by theaddition of the desired number of bars H and P. Combined with the barsA, H, and P are longitudinal bars 13, D', and N, arranged, as heretoforedescribed, in positions intermediate the tensional regions, at thecrown, and near the base in the extrados, respectively. The longitudinalbars are or are not connected with the transverse bars, as may be foundmost suitable to meet the requirements of the particular case.

In the form shown in Fig. 1l I employ the bars F and O, the former beingshown in Figs. 4 5 6, duc., and the latter in Fig. 9, said bars havingthe functions and advantages stated in the description of the formsshown in these figures. Combined with these bars are the longitudinalbars D, arranged as heretofore described, B occupying positionsintermediate the tensional regions and C, which are placed opposite thetensional region, in the extrados. There are also longitudinal barswhich are placed in the intrados some distance below the bars B andwhich assist in transferring the strains from concentrated loads appliedin their regions to the adjacent transverse bars F and O. Thelongitudinal and transverse bars may be connected together, if thoughtdesirable.

Fig. 12 shows a form of arch having the bars A and F combined with thelongitudinal bars B, C, and N, heretofore described. In each of theforms shown in Figs. 9,10, 11, and 12 the two sets of transverse barsmay be secured together at the crown, if desired.

Figs. 13 and 14 show a form of tubular arch in which a continuous barRis passed spirally around and around Within the structure, preferablynear the plane midway between the intrados and extrados. Combined withthis bar are longitudinal bars S, which give rigidity and strength tothe structure and distribute strains due to concentrated loads over agreater number of convolutions of the bar R. As will be understood, thetubular arches may be circular, elliptical, oval, or any other suitableshape in cross-section.

In Figs. 15 and 16 another form of tubular arch is shown, in which twocontinuous bars R and R' are employed, the bar R being within and beingwound in the opposite direction to the bar R. Combined with these barsare longitudinal bars S and S', which lie next the bars R and R',respectively, and

may or may not be connected thereto, as seems most desirable. Instead ofhaving the extrados and intrados lines parallel, as shown, the formermay be developed into other forms, such as that shown in Fig. l. In theforms shown in Figs. 13 to 16 a series of closed rings arrangedtransverse to the axis may be substituted for the spiral bars, ifdesired.

Throughoutthe specification and claims the term loar7 is used in ageneric sense and is intended to include all forms of plain, corrugated,or other shaped bars, angles, dac., or

all forms of built-up sections of bars held to` gether by means ofrivets, bolts, or otherwise, so as to form a continuation of the metalmember. The term concrete is used to cover mortar or mortar incombination with broken stone, gravel, and the like, or it may alsoinclude brick or stone masonry laid in mortar.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, isl 1. In a concrete arch, the combination ofibars transverse to the axis of the arch and ipassing through regions oftension in both lintrados and extrados, and other bars extendtinglongitudinally with the axis of the arch. 2. In a concrete arch, thecombination of bars transverse to the axis of the arch and passingcontinuously through all the regions of tension in intrados or extradosot' the arch, other transverse bars passing through regions of tensionin both intrados and extrados of the arch, and longitudinal barsextending in the direction of the axis, substantially as described.

3. In a concrete arch, the combination of bars transverse to the axisand passing continuously through all the regions of tension in one sideof the arch, other transverse bars in one of the sides of the arch andpassing through part only of that side, and longitudinal bars extendingin the direction of the axis.

4. In a concrete arch, the combination of bars transverse to the axis ofthe arch and passing continuously through all the regions of tension inone side thereof, other transverse bars in one of the sides of the archand passing through part only of that side, and longitudinal barsattached to the transverse bars at points intermediate the tensionalregions.

5. In a concrete arch, the combination of bars transverse to the axis ofthe arch and each passing continuously through regions of tension inboth intrados and extrados, and other bars extending longitudinally withthe axis of the arch, said longitudinal bars being attached to thetransverse bars at points intermediate between the intrados and extradostensional regions.

6. In a concrete arch, the combination of bars transverse to the axis ofthe arch in both IOO ICS

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roaree intrados and extrados, the bars on one side extendingcontinuously through all the regions of tension on that side, and thoseon the other side extending through a single tensional region and farenough beyond to give secure anchorage, and longitudinal bars at tachedto the continuous tensional bars, substantially as described.

7. ln a concrete arch, the combination of bars transverse to the axis ofthe arch and extending continuously1 through all the regions of tensionin one side of the arch, othertransverse bars att-ached thereto andpassing through the body of the arch and into the other side where theypass through a single tensional region, and longitudinal barsextendingin the direction ot' the axis oi' the arch.

S. In a concrete arch, the combination of bars transverse to the axis ofthe arch in the intrados thereof, and other bars in the extradosthereof, the bars in the extrados being opposite the spaces betweenthose in the intrados, with other bars extending in the direction of theaxis of the arch, substantially as described.

9. In a concrete arch, the combination of bars transverse to the axis ofthe arch in the intrados thereof, and other bars in the extradosthereof, the bars in the extrados being opposite the spaces betweenthose in the intrados, with longitudinal bars attached to the transversebars n intrados or extrados at points intermediate the tensionalregions, substantially as described.

10. In a concrete arch, the combination of bars transverse to the axisof the arch and passing continuously through all the regions of tensionin both intrados and extrados, other transverse bars passing throughpart only of the tensional regions and far enough beyond to give secureanchorage, and longitudinal bars extending in the direction of the axis.

ll. In a concrete arch, the combination of bars transverse to the axisofthe arch and passing continuously through all the regions of tensionin both intrados and extradospvith longitudinal bars extending in thedirection of the axis.

l2. ln a concrete arch, the combination of bars transverse to the axisof the arch and passing continuously through all the regions of tensionin both intrados and extradosnvith longitudinal bars extending in thedirection of the axis and being attached to the transverse bars atpoints intermediate the tensional regions, substantially as described.

13. ln a concrete arch, the combination of bars tranverse to the axis ofthe arch and passing continuously through regions of tension in bothintrados and extrados, and other bars extending longitudinally With theaxis of the arch, substantially as described.

l-l. ln a concrete arch, the combination of bars transverse to the axisof the arch and extending continuously through all the regions oftension in one side of the arch, other transverse bars attached theretoand passing through the body of the arch and into the other side, andlongitudinal bars extendingV in the direction of the axis.

ln testimony whereof I affix my signature in the presence of twoWitnesses.

XVALTER C. PARMLEY. Witnesses:

S. E. FoULsZ, JAMES T. HARDING.

